The latest Demon Slayer movie, Demon Slayer: Infinity Castle (Part 1) , has a confirmed runtime of 155 minutes , which is about 2 hours and 35 minutes.

Quick Scoop: How long is the Demon Slayer movie?

If you’re searching “demon slayer movie how long,” you’re almost certainly hearing the buzz about the big new arc on the big screen.

  • The upcoming Demon Slayer: Infinity Castle movie (Part 1) is 155 minutes long.
  • That’s 2 hours 35 minutes of non-stop Demon Slayer.
  • It’s longer than Demon Slayer: Mugen Train , which was about 117 minutes (1 hour 57 minutes).

So if you’re planning a theater trip, expect it to take close to three hours once you add trailers and credits.

How it compares to Mugen Train

Here’s a quick runtime comparison in simple form:

  • Demon Slayer: Mugen Train – 117 minutes.
  • Demon Slayer: Infinity Castle (Part 1) – 155 minutes.

That means Infinity Castle runs almost 40 minutes longer than Mugen Train, giving more room to adapt the dense Infinity Castle arc without rushing key battles and story beats.

Why fans are talking about the length

Anime and movie outlets are calling out how unusually long this film is for an anime movie.

  • Some coverage notes that 155 minutes makes it one of the longer anime films out there.
  • Articles and news blurbs describe the runtime as a “treat for fans” because it suggests the arc won’t be overly compressed.

On forums and social platforms, the length is a big talking point: people are excited about more content but also joking about needing snacks and bathroom planning for such a long anime screening.

Latest news & forum-style chatter

Recent entertainment and anime news sites highlight three main angles:

  1. Epic runtime
    • 155 minutes is repeatedly highlighted as a standout stat in headlines and thumbnails.
  1. Franchise endgame energy
    • This movie is framed as “the beginning of the end” for the series’ story, which partly explains the extended runtime.
  1. Comparison with previous releases
    • Many pieces explicitly compare it to Mugen Train and mention how much longer Infinity Castle is.

A typical vibe from fan conversations looks something like:

“2 hours and 35 minutes in the Infinity Castle? I’m not moving from that seat until the credits stop rolling.”

TL;DR

  • Demon Slayer: Infinity Castle (Part 1) runtime: 155 minutes (2h 35m).
  • That’s longer than Mugen Train ’s ~117 minutes.
  • It’s being talked about as an unusually long and packed anime movie, setting expectations for a big, detailed adaptation of the Infinity Castle arc.

Information gathered from public forums or data available on the internet and portrayed here.